The roles of integrin αvβ6 in cancer

Integrins are a family of heterodimeric cell surface receptors that are expressed in most cells, where they mediate cell-cell and cell-extracellular matrix (ECM) interactions. Integrin alpha v beta 6 is a heterodimer with ay and beta 6 subunits. It is epithelial-specific and strongly induced during wound healing, inflammation and carcinogenesis. Integrin alpha v beta 6 is considered to be a prognostic indicator because it is up-regulated in various types of cancers and integrin alpha v beta 6 expression correlates with the survival time of patients. A large body of evidence suggests that integrin alpha v beta 6 is of great significance in tumor progression, as integrin alpha v beta 6 has been demonstrated to modulate numerous malignant behaviors of tumor cells. A number of classic oncogenic signaling pathways are involved in integrin alpha v beta 6-mediated tumor progression. The expression characteristics and vital effects of integrin alpha v beta 6 in the progression of tumors has led studies to focus on integrin alpha v beta 6-targeted tumor imaging and tumor therapy, which have subsequently made integrin alpha v beta 6 a promising target for clinical examination and treatment. This review provides an overview of the current understanding of the roles and underlying mechanisms of integrin alpha v beta 6 in tumors. Furthermore, the common links as well as discrepancies between independent studies are also discussed. (C) 2017 Elsevier B.V. All rights reserved.